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charset="US-ASCII"; x-default=true X-Rspamd-Queue-Id: 16EEF160004 X-Stat-Signature: 8y1ww7b6ctrh1fbydjnuh43bo739y9u5 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1774316053-929217 X-HE-Meta: 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 U7qwyfes +S8bUvF9E1pEpuZbnK6Pk/9wLPfS5t6lyGiKind/ggzXRBm26nY80i/f2QmCQdOb7TMoidxRu8alAVKx1qZhTNWgj/PNCuXkglsq0MuJODBRKXNpSEnWIkVyJYIrd9XOowkIp9vbu1OtxD9E1CVu1JC2NWLZPUg0BMJpAEoQR8IML5FetUaxT7gyxXINLNUWIsd5lML+KA51huIHSDy8ITZDHDgx2SspkcFW2OEj+0EaK46DWMdO2rJyRQX/2zgtdBoDMUpaD0ACC0+iXx27t2267woEPsrIXxFoejlTRgjqHGebfBFgnHTiskonr/LVB4E29prPxMqtBQ3zX5Ei+WOkx6bEpmztKa+35IAx9FdJ61KINIVsMo012iyD1ItZCxnLkF3cb9pfnINY= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Add two more checks for buflen and numwritten. The buflen should be at least one, otherwise the 'buflen - 1' could underflow and cause trouble. The numwritten should be equal to 'buflen - 1'. The test will exit if any of these conditions aren't met. Additionally, add more print information when a write failure occurs or a truncated write happens, providing clearer diagnostics. Signed-off-by: Chunyu Hu --- Changes in v6: - save/restore errno before and after the close(), so the log could show the correct error info on failure. Suggested by AI. Chagnes in v5: - new patch for making improve on write_file. Add more safety checks and diagnostics info in log --- tools/testing/selftests/mm/vm_util.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index ad96d19d1b85..572ccb99de8e 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -767,15 +767,23 @@ int unpoison_memory(unsigned long pfn) void write_file(const char *path, const char *buf, size_t buflen) { - int fd; + int fd, saved_errno; ssize_t numwritten; + if (buflen < 1) + ksft_exit_fail_msg("Incorrect buffer len: %zu\n", buflen); fd = open(path, O_WRONLY); if (fd == -1) ksft_exit_fail_msg("%s open failed: %s\n", path, strerror(errno)); numwritten = write(fd, buf, buflen - 1); + saved_errno = errno; close(fd); + errno = saved_errno; if (numwritten < 1) - ksft_exit_fail_msg("Write failed\n"); + ksft_exit_fail_msg("%s write(%s) failed: %s\n", path, buf, + strerror(errno)); + if (numwritten != buflen - 1) + ksft_exit_fail_msg("%s write(%s) is truncated, expected %zu bytes, got %zd bytes\n", + path, buf, buflen - 1, numwritten); } -- 2.53.0